Does launching projectiles significantly alter the orbit of Hayabusa2? | AskScience Blog

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Friday, April 5, 2019

Does launching projectiles significantly alter the orbit of Hayabusa2?

Does launching projectiles significantly alter the orbit of Hayabusa2?


Does launching projectiles significantly alter the orbit of Hayabusa2?

Posted: 05 Apr 2019 06:52 AM PDT

I saw the news today that the Hayabusa2 spacecraft launched a second copper "cannonball" at the Ryugu asteroid. What kind of impact does this have on its ability to orbit the asteroid? The 2kg impactor was launched at 2km/s, this seems like it would produce a significant amount of thrust which would push the spacecraft away from the asteroid. So what do they do in response to this? Do they plan for the orbit to change after the launch and live with it? Is there some kind of "retro rocket" to apply a counter thrust to compensate for it? Or is the actual thrust produced by the launch just not actually significant? Here is the article I saw: https://www.cnet.com/news/japan-is-about-to-bomb-an-asteroid-and-you-can-watch-here/

submitted by /u/showponies
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[Astronomy] Do giant, highly oblate planets exist?

Posted: 05 Apr 2019 06:51 AM PDT

I'm reading one of the first hard science fiction novels written: Mission of Gravity by Hal Clement. In it a world called Mesklin is described with, among others, the following characteristics:

  • supergiant,
  • highly oblate,
  • strong gravity (a gee force gradient, starting at 3 g on the equator, and ending at 665 g on the planet's poles).

I'm very curious if this falls in the technically possible category or if we have actually found a planet that has the rough characteristics as described.

submitted by /u/nevahre
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Why can excited monoatomic gases (eg neon) emit photons but not homonuclear molecules (eg dinitrogen)?

Posted: 05 Apr 2019 07:00 AM PDT

this is from the wikipedia page https://en.wikipedia.org/wiki/Carbon_dioxide_laser

From the article: electron impact excites vibrational motion of the nitrogen. Because nitrogen is a homonuclear molecule, it cannot lose this energy by photon emission, and its excited vibrational levels are therefore metastable and relatively long-lived.

submitted by /u/nicktohzyu
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Why are testicles considered a gland and ovaries are organs? Or what is the difference between a gland and an organ?

Posted: 05 Apr 2019 04:19 AM PDT

Are there any herd animals that exhibit sacrificial behaviour when being hunted by predators?

Posted: 05 Apr 2019 03:26 AM PDT

Have there been any cases where the old/weak/infirm members of the herd have sacrificed themselves to predators to allow the greater herd and younger animals to escape?

submitted by /u/DubstepBurrito
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Do people native to high altitude places experience any negative effects on their health when at sea level?

Posted: 05 Apr 2019 01:17 AM PDT

Those huge cargo ships and oil tankers have a really small anchor compared to the overall size of the ship. How does such a small anchor manage to keep the ship in place?

Posted: 05 Apr 2019 04:44 AM PDT

Is the light from the sun mostly incandescence or a byproduct of fusion?

Posted: 04 Apr 2019 03:36 PM PDT

I imagine it's a combination, but are we mostly seeing radiant energy cast off from fusion, or the incandescent glow of the hot matter afterwards?

submitted by /u/oliksandr
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How do we tell the difference between convergent, divergent, and parallel evolution?

Posted: 05 Apr 2019 05:20 AM PDT

Because for the most part, all we get to see is a snapshot in the chain, how can we tell if species are related or not?

submitted by /u/Ozurip
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What is the effect of resellers on the economy?

Posted: 04 Apr 2019 06:05 PM PDT

I'm not refering to retailers per se, because I can understand the effect they play: grouping the products in a physical location.

These resellers end up raising the prices of a product that wouldn't cost that much otherwise. I'm not talking about speculating that a product will become valuable at a later date, I'm talking about products in established markets (proven to be stable, people have been buying it for years) being bought at a lower price and then resold for a small profit.

What would happen to an economy where these people didn't exist? Would prices keep going down if the demand was low? Because these people create a fake demand for the products.

Is there more I can read about this subject?

submitted by /u/pphp
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If you shoot a gun while on a space walk, would the bullet be able to escape the solar system?

Posted: 04 Apr 2019 04:02 PM PDT

How has the widespread use of penicillin as an antibiotic affected the Penicillium fungi in the wild? Has the fungi become any more vulnerable to bacterial infection due to penicillin-resistant bacteria as a result of its use?

Posted: 04 Apr 2019 10:08 PM PDT

Is it possible for two embryos with different fathers to fuse and create a human chimera?

Posted: 04 Apr 2019 10:29 AM PDT

If superfetation occurred with each embryo having a different father, could the death and absorption of one result in the creation of a human chimera with two different fathers? Would the product even be viable?

submitted by /u/neptunesbane
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Do tidal forces from the Moon have any effect on the Earth's mantle?

Posted: 04 Apr 2019 10:07 PM PDT

Relationship, even an equation between prevalence of atoms/molecules and stability?

Posted: 04 Apr 2019 07:55 PM PDT

This may seem an elementary relationship, but is there an equation out there, like a conversion function that takes some index value that represents an atom or molecules prevalence in the universe and outputs the relative stability of that atom or molecule? And vice versa?

I couldn't find anything on google about it. Apparently there is a weak relationship between nuclear binding energy and the as you go up the periodic table from hydrogen. I don't think that's relevant, but it would make intuitive sense if the more stable an element or molecule (like H20 or Helium gas) are generally more prevalent in the universe than less stable ones...and if so, is there some sort of equation devised to easily calculate one to get the other? Is it in the Handbook of Chemistry or something like that?

submitted by /u/ilumrf1986
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Second mode waves in boundary layers and instability?

Posted: 04 Apr 2019 06:42 PM PDT

Can anyone explain what second mode waves are in terms of fluid mechanics and what boundary layer instability means?

submitted by /u/nasawesome
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When drinking water, do Hydronium and Hydroxide ions serve different purposes when absorbed by the body?

Posted: 04 Apr 2019 09:19 PM PDT

How do we know that the four legged whale that was just announced to be have been found in Peru should be classified as a Whale?

Posted: 04 Apr 2019 08:22 PM PDT

I would assume it has some to do with similar bone structures and stuff but I was hoping to learn some specifics as to how we know this should be classified as an earlier version of whales and not some other creature. Is there a way to tell just based off of bone structure that it should be classified as a mammal? I would think that's an important early step. Thank you!

submitted by /u/jobletofscience
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Could someone help me with Constant speed of light and all that?

Posted: 05 Apr 2019 01:16 AM PDT

I don't get time dilation, lenght contraction and the constant speed of light, so I hope someone can help me out.

First off, instead of lenght contraction, time dilation and the constant speed of light, why can't I say that light slows down when I approach it and accelerate when i move away from it? To me it seems like I would get the same results ether way. I would measure the speed of light as c no matter how fast I'm moving or in which direction. What law am i violating?

So to a little tought experiment. I stand between two laserpistols. when I press a button a signal goes to both lasers and they fire when they recieve it. Will the two lasers reach me at the same time if I move towards either pistol? If not, then what is so special about light?

If the signal sent two footballs towards me, the ball I moved towards would be the first to reach me because:

  1. the speed of the ball I am moving away from (ball A) would decrease relative to me and vice versa for ball B.
  2. the distance ball A has to move to reach me increases, and vice versa for ball B.

So how does light solve this? (Given that light really do hit me at the same moment no matter my movement and given my "light speeds up and down according to my motion"-statement is wrong).

submitted by /u/Kingchachacha
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What is the depositional environment for a low permeability carbonate reservoir?

Posted: 04 Apr 2019 09:20 PM PDT

I'm currently working on a design project that has a low permeability carbonate reservoir with a 21% porosity. So far I've been reading papers but not understanding what is happening with the geology. Any geologists have an explanation? For context, the reservoir I am studying is located in the Ratcliffe beds of the Oungre evaporite (Midale evaporite).

submitted by /u/andarott
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Why are depleted uranium penetrators "self sharpening"?

Posted: 04 Apr 2019 10:46 AM PDT

I keep hearing that depleted uranium is "self sharpening" and the best explanation I've found is that DU burns away on the edges. While I don't doubt this is true, it still doesn't explain what exactly it is about DU that causes it to happen instead of having the nose rounded over.

(and yes I already know about post-pen effects so you don't need to explain that)

submitted by /u/TheDapperDugong
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Adding water to paint makes it flow better and lay more flat initially. Does adding water make the paint dry more quickly?

Posted: 04 Apr 2019 09:03 PM PDT

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